This invention relates to arrangements for retrieving information via content addressable techniques and, more particularly, relates to a technique for increasing the speed and flow of information across the user-machine interface of such arrangements.
In a patent application of C. S. Roberts, Ser. No. 775,114, filed Mar. 7, 1977, now U.S. Pat. No. 4,118,788 issued on Oct. 3, 1978, and of common assignee, an associative information retrieval system is disclosed utilizing a superimposed code word technique. The superimposed code words are generated from key values contained in individual records collectively stored in an indexed mass memory. The superimposed code words are stored in an auxiliary file which is associatively searched using a query mask to identify matches. The query mask is formed from key values in information obtained from the user by the same superimposed code word technique. In the auxiliary file, an associated index code is provided for each superimposed code word. The associated index code for each matching superimposed code word serves to locate the correspondingly indexed record entry in the mass memory from which all the information is retrieved.
The foregoing system is advantageous to both the user and system designer. For the ease of the user, searching and retrieval functions in the system are independent of the order of key words received. Hardware implementation of the searching technique may utilize parallel processing design to achieve high speed operation. Furthermore, the system designer may utilize apparatus that may be expanded gracefully as the size of the data base grows. Although these advantages are important, further benefits will result if information were being processed as soon as it is received so that even the naive and occasional user may be guided while obtaining information with much simpler protocols than heretofore possible.
It is accordingly an object of this invention to provide an arrangement which operates using a minimal amount of information and speeds up the response time to the user.
A related object is to reduce errors by keeping the amount of information required to do a retrieval operation to a minimum.
Another object of the invention is to provide information to the user on the progress of the searching process and thereby educate the user as to the best query strategy.